1. Field of the Invention
The invention relates to safety head gear, safety caps, hard hats and the like and particularly to an energy absorbing suspension therefor.
2. Description of the Prior Art
Regulations of the federal agency OSHA require that safety caps must meet certain specifications directed to protect the wearer's head from being struck and injured by objects and to lessen the impact thereof transmitted to the wearer's head.
In a number of prior art safety caps the suspension includes a crown piece, crown straps and anchor lugs, which are as disclosed in U.S. Pat. Nos. 3,422,459, 3,909,846 and 2,946,063 molded in one piece from plastic material. During impact the shell resists the force of the falling object by being deformed and displaced closer to the crown of the head. During displacement only the strap portions of the unitized plastic suspension begin to yield, stretch or elongate and thereby absorb some of the shock of impact.
In other safety caps disclosed in U.S. Pat. Nos. 3,192,536 and 3,237,201 the suspension is an assembly of individual flexible parts. One or more of the flexible parts are or have portions of different length which are either elastically deformed, stretched or elongated in a sequence determined by its length to absorb a portion of the shock. In each case the shortest portion is stretched or elongated first to absorb part of the shock followed by the next longest and so on to absorb additional shock.
Applicant's safety cap differs from those of the prior art in that the suspension includes crown straps connected to first elastically yieldable, then rupturable and thereafter controlled plastically deformed and finally arrested energy absorbing portions of detachable connecting means. The connecting means have head portions attached to anchor means in the shell. A portion of an impact or shock is first absorbed by a wedging action which continues until the heads are fully seated against the anchor means.
Further amounts of the impact energy are absorbed by elastically deforming, bending and stretching the energy absorbing portions into adjoining apertures followed by partial rupture of and controlling the failure and plastic deformation by progressively or successively bottoming the plastically deforming energy absorbing portions against adjoining control means of predetermined size and shape.